RFR: 8350048: Enforce threading restrictions for show and hide methods in Window, Control, and Skin [v3]

[Kevin Rushforth]

On Thu, 27 Feb 2025 15:57:07 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> - enforced fx application thread
>> - clarify doc where an `IllegalStateException` can get thrown, such as hide() and show()
>> - clarified `ComboBoxBase::show`
>> - added a headful test `TestThreadingRestrictions`
>
> Andy Goryachev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   review comments

The updated docs look good. Go ahead and create the CSR.

-------------

PR Comment: https://git.openjdk.org/jfx/pull/1717#issuecomment-2690958410